The invention relates to an ultrasonic imaging apparatus operating according to the impulse echo method, comprising an ultrasonic transducer for scanning, particularly also for linear scanning, of an examination subject, and comprising an image display device for representation of the ultrasonic-echo signals in the form of an echo display image.
In apparatus of this type, among which are very generally included so-called compound-scanners, sector-scanners, or also rotational and array B-scanners, and/or also random A-scanners and Doppler-scanners, the quality of the ultrasonic echo images produced still leaves much to be desired. In particular, an improved transverse resolution is desirable, and echo-producing structures which are tangentially subjected to ultrasound should be better capable of representation. It is known from the physics of sonic fields that both cited properties are improved with an increasing sonic frequency. However, an increase in the frequency beyond the hitherto conventional values would lead, in the case of the known apparatus, to a reduction of the maximum possible penetration depth of the ultrasound in the area under examination.